Mechanically moved chain grate



Sept. 7,1937. E. A. LEMAIRE MECHANICALLY MOVED CHAIN GRATE Filed March 21, 1955 0 e sneets-shee2 III/IIIIIIIII/III/Il Sept. 7, 1937. E. A. LEMA I RE 2,092,080

- MECHANICAL-LY MOVED CHAIN GRATE Filed Marchzl, 1935 6 Sheets-Sheet 6 f g/a.

/A/I/ZA/TOB EoouARo Aueus TE [EMA/R5 4 BY ATTORNEYS.

Patented Sept. 7 1937 *UNITEDT 'sTI'A TEs MECHANICALLY ovnn CHAIN GRATE Edouard Auguste Lemaire, Grenoble, France, as-

signor to Societe Anonyme ditte: La Mure Combustibles et Industrie, Grenoble, France Application March 21, 1935, Serial No. 12.130 InFrance March 26, 1934 n v s (or 110-40) j This invention relates to a chain grate for small furnaces andrefers more particularly to a chain grate for. house-boilers having a small grate surface.

" The grate constructedaccording to the-present invention is characterized by a chain in which the link rods constitute the pivots of small bars which extend between the opposite links of saidchain,

the alignment of the tables of said bars designed to form the grate surface being automatically upper strand of the chainrest one upon the other witha shoulder designed to stop the links inwardly. w 0

0 The links are stopped outwardly preferably by n 30. means of a-conically bored ring lockedby the spreading apart of the two inembersof the previously Split I'Od end;*" n n e The small barsare provided on one side, preferably on the opposite side, with a bearing surface 1; 35 and with a restingboss constituted so as to'leave a predetermined space forj the"dr'au"ght, between two successive sm'all bars, alccordingto the size of the fuel tobeburnt. a

There is preferablyone or: more middle bars 39 provided with blast notches uponevery link rod according to the width f the grate andtwo' side bars withoutnotches; a

exposed to the fire withrecesses preferably coated The chain is guided between border parts to' which are addedat' the top two-guides for' the bars, "one of said guides which'is stationary presenting an incline upon which freely rests the other angle" shaped. part that bears on the other hand upon the edge of the bars of the upper chain strand.

Draught distributing boxes provided with a dust extracting device are r placed between the two strands of the chain grate below-the grate plane. A heavy metal part pivotally mounted upon a horizontal shaft-outside its-center of gravity so as to come to bear byits own weight uponthe end of the grate plane serves to remove the-clinker. 1 The appended drawings show by way of exl ample one mode of construction of agrate for The said bars are provided upon thesurface small furnaces constructed according to" the present invention.

Fig. l is a longitudinalsectional view showing diagramatically in elevation the grate applied to the furnace of a central heating boiler. n '5 Fig. 2 is a longitudinal section in part diagrammatic illustrating the grate with its fittings.

Fig. 31s a part transverse 'sectionalview of the chain taken along the rod of one'ofthelinks.

Fig. 4 is a plan view of links and '10 established due to thefact that the bars of the y 0 Fig.5 is a corresponding side view.

Fig.16is a part transverse sectional view of thegrates The grate chain is'constituted by a. chain havf 1! ing extended rods-which are'surrounded bytubu-" larstages; they may alsobe provided at both ends Figs. 7 and 8' are respectively a sectional view and a part plan view of a middle bar.

Figs. 9 andIIO are respectively a sectional view I and a partplan view of a border bar. 1

Fig. 11 is a sectional view of a bar in combination with its pivotal support when normally in position.

Fig. 12 is a similar "sectional view of a bar provided with another type of support. v

Figure 13 isa plan view showingthe front portion of the grate. i

The grate illustrated in the appended drawings comprises a set of small bars 0 I, mounted upon the rod 2"of the chain linksjaround which they may pivot. The-chain has long rods 2uand tubular stays'3, as indicated in Fig. 3.' It'may also be 0 I provided with rods having narrower ends 2 (Fig.

6). The rods are split or open at} both ends for a few millimeters and'they carry-washers 2 hav- 1 2a slightly conical bore which are'designed to retain the links 4) 4 4. This flaring 'of the washerslnensures ard'allo'ckingby simply spreading 3 out the end opening with a tool.

Thechainsare very compact and the outer diameter of the end washers is approximately that of the links. Said devices have been "devised in order to baflie the'flow of air alongthe chains 40 and to improve the division into compartments.

For very small sizes, the chain is fed by means of a shaft5 provided with toothed wheels S and travels at its other end upon a cylindrical guiding surface 6. For theusuallchains a second shaft carrying also toothed wheels is substituted for i The depth of the coal upon the gratemay becontrolled by means of a coal hopper provided with a feed regulator 8. A firing arch 8 (Fig. 1) may be arranged near thefeed regulator according to the grade of the fuel to be consumed. In the case of fuels which .75 mentor the bar. a

bar; said surface and said boss areso constructed that the bars not only overlap each other but that between two adjacent bars there remains a free 15 space e for the draught.

determined width for every type of grate 'constructed for burning a fuel of agiven size.

The bars may be constructed so'as to form a unit between two opposite chain links but a pluzo rality of members are preferably used, that is: one or more middle bars I C (according to the widthof thegrate) provided with blast. notches I asshown in Figs. .7 and 8,.and two side, bars IL without blast notches, as indicated in Figs. 6 H

25 and9. z

The side bars which-have blastnotches com pensate the action of the walls upon the coal bedl as they cause a slightslackening of the combus tion at these points'where ittends to. loe'mcore 30 accelerated than inthe middle. I i

The bars are shaped in such manner thatj each since this always ensures a good utilization of the n metal. Their sides "present moreovera general 36 incline inferior to that-of the natural descent ofthe coal with theobject (1st) to prevent the pea. coal from fallinginthe draught distributing boxes and obstruct ;themv after a time and, (2nd) to compel the-blast air directedbythe notches l to 40 impinge obliquely uponthe coal. This arrange.- ment produces a very good distribution of the air for combustion and allows stronger blowing withe In this manout disintegrating thelayer of fuel ner the rate of combustion may be substantially recesses l The object of-said recesses is to 1'6,-

1 1 duce the heat upon that portion of the bar, care 50 being taken to fill them withrefractory cement or to leave thezashes which-gather after a few days and act as laggingapplied upon a considerable portion of the surfaceexposed to theLfire. The

metal and protects it.; i

The recesses i are p r'fiferably iillediwith refractory cement so as to prevent the metal being actedl upon-by the fusible products that are found in anthracite coals. The operation may be effected by simply injecting upon the strongly heated bars water containing lime or otherrefractory materials which due to immediate vaporization leavea,

coating which adheres upon the metal.

5 The bars are all pivotally mounted upon the chain rods 2 or upon the tubular stays 3 surrounding them by means of a support 9 which may consist of a tube and an!) welded together as shown in Fig.11; this support may also consist of a piece mofsheet metal folded in the'shape of a'clipor strap provided with an eye, asseen inFig. 12 in which.

the bar is fastened. Said support is mounted around the rod withconsiderable play so as to move freely and not prevent Said space hasa pre- Patent of thejUnited StatesisL. .1

the. pivotal move- The entire grate is moved by the rods 2 and slides slowly upon two upper side guides II) and upon two lower flanges ll of the frame (Fig. 6). The grate is situated above the transverse partitions which dividethe draught distributing boxes I2 '(Figs. 1 and 2) formed under the upper strand of the chain grate. The draught distributing boxes may be provided with doors l3 for the rev moval of ashes which may have fallen in said boxes. I

'The border parts of the frame preserve the chain from the action of the fire. They are also arranged for guiding the translating movement of the I bars. A certain play must normally exist between their inner vertical sides and the ends of parts; the part which isstationary, as seen in r V Fig. .6, is bolted tothe' side members ii of. the frame and the other part is has the shape of a widely opened angle resting-freely between the first member and the outeredge of the bars,-

The air tightness resulting from the weight of the angle-shapedipart is sufficient toprevent the passageof air: without necessitating an excessive force for the, advance movement of the grate. The

H V v. part: IS the angle of which is calculated in. such a. 7 section should receive an equal amount of'heat manner as to'prevent any wedging, follows the grate in its transverse expansion. It also bears at allows when necessary to remove the clinker that adheres to the bars. The clinker is subsequently emptied into the hopper-l8. v v

WhatI claim and desire to by Letters 40" presses upon the grate by its own weight and I 1. A.mechanically, moved gratefor fur-- V naces, which comprises links extending along opposite sides of thigrate and rods extending across I the grate and pivotally, connecting 'the links to forma chain, bars pivotally mounted uponsaid chain rods, said bars comprising surfacesbearing 'one upon'theother, whereby the upperfs'urfaces ashes within the recesses are hardened by fire and 55soon'form ahard coating which adheres to the ofthe bars in the upper chain strand come' auto,- matically in line to form the'grate; surface, and

means for laterally guiding thechainand the 7 bars.

' 2. Amechanically movedi.for small furnaces which comprises links extendingalong opposite sides of the grate and rods extending across .the grate and pivotally connecting the links/to form a chain, ,tubuIarstays around said rodsto determine the distance between-the linksat opposite sides of the grate; gratelbars pivotally mounted upon said, tubularstays and, having up+ come automatically-in linein such, a manner as to constitute the grate surface,. and means for laterally guiding the-chain and the bars.

3. :A mechanically moved grate for small furnaces which. compriseslinks extending along opposite sidesof thegrate androds extending across the grate and pivotally connecting the linksto form a chain, said rods being provided with shoulders for determining the distance between links at opposite sides of the grates, and having split ends, washers formed with a conical opening which are locked by the drawing-apart of the split ends of the rods in order to prevent the removal of the links, grate bars pivotally mounted upon said chain rods and having upper flat surfaces, said bars presenting surfaces which bear across the grate and pivotally connecting the links to form a chain, grate .bars pivotally mounted upon said chain rods and having upper flat surfaces, supports constituted'by a sheet metal part folded in the shape of a strap and provided with an eye for pivotally supporting said a grate bars upon said chain' rods, said bars presenting surfaces bearing one upon the other,

' whereby the upper surfaces of the bars-in the upper chain strand come automatically in line in such a manner as to constitute the grate surface and means for laterally guiding the chain and the bars. a

5. A mechanically movedgrate. for small furnaces which comprises links extending along opposite sides of the grate and rods extending across the grate and pivotally connecting the links to form a chain, two solid bars and at least one middle bar provided with notches, said bars being pivotally mounted upon every chain rod and presenting surfaces bearing one upon the other, whereby the surfaces of the bars in the upper strandoome automatically in line in such a manneras to" constitute the grate sur- 1 face,'andidraught distributing boxes arranged heneath the upper chain strand. 1 6.- A mechanically moved gratefor small furnaces, which compriseslinks extending along oppositegsidesof the grate and' rods extending across the grate'and pivotally connecting the links to form achain, tubular stays around said rodstodetermine the distance between the links at'iopposite sides of the grate, said rods having split'ends, washers formed with a'conical opening which are locked by the drawing-apart of the split ends jofthe rods;in order to preventthe removalof the links, two solid border bars and at least one middle barlprovidedwith notches, said barsbeing pivotally niounted upon every, chain rod and presenting surfaces bearing one upon, the other, whereby ,the surfaoes of the bars in the upper chain strand, come automatically in line v v in such'a manner as to constitute the grate surface, draught distributing boxes arranged beneath the upper chainstrand, longitudinal members for guiding and supportingonboth sides the two chain strands,'{two other longitudinal members added on both sides, tojthe' upper chain strand, guiding membersdesigneda to guide the bars or said upper strand,'one of the' last-menv tioned members which is stationary being formed with an incline, while theother one of the lastmentioned members is fofgangizlarshape and bears, on one side upon'jsaid incline and on theother side against the edge of the bars in the upper chain :strandii a nnomnn Accusm LEMAIRE.

Isa 

